Abrasive wheels for cigarette lighters and method of making same

ABSTRACT

Abrasive wheel for cigarette lighters consists of cylindrical plate having teeth along one edge and a knurled outer cylindrical surface. The wheel may be formed by bending a strip into a cylinder or stamping a circular plate into the shape of a cup.

1451 July 8,1975

Hocq

[54] ABRASIVE WHEELS FOR CIGARETTE 2,252,676 8/1941 431/139 LlGH-TERSAND METHOD OF MAKING 3,129,505 4/1964 COX ll3/i [6 D SAME 3,262,2897/l966 Biesenbach 43l/277 [75] Inventor: Robert Hocq,Boulogne-sur-Seine, FOREIGN PATENTS ()R APPLICATIONS France 915,405[/1963 United Kingdom 431/274 [73] Assignee: SocieteFranco-Hispano-Americaine germany rance ggzg Sam 744,264 1/1933 France431/140 [22] Filed: Apr. 24, 1973 I Primary ExammerCarroll B. Donty, Jr.PP 353,990 Attorney, Agent, or FirmBriseb0is & Kruger [30] ForeignApplication Priority Data Apr. 26, 1972 France 72.14817 [57] ABSTRACTAbrasive wheel for cigarette lighters consists of cylin- 431/ 12 3 63;drical plate having teeth along one edge and a knurled 58] Fieid outercylindrical surface. The wheel may be formed by 13"6 bending a stripinto a cylinder or stamping a circular plate into the shape of a cup.

56 References Cited 1 U T STATES PATENTS 3 Claims, 5 Drawlng Figuresl,951,l5l 3/l934 Hopkins ..1l3/ll6D 1 ABRASIVE WHEELS FOR CIGARETTELIGHTERS AND METHOD OF MAKING SAME SUMMARY OF THE INVENTION Thisinvention relates to abrasive wheels for cigarette lighters, that is tosay, wheels which are adapted to frictionally engage a flint to ignitethe lighter, as well as to methods of manufacturing these abrasivewheels.

Up to the present time these wheels for cigarette lighters have beenmade by cutting them from large steel rods and machining them. Themachining consists essentially in forming a bearing in the wheel so thatit may be mounted on a pivotal axis, cutting one of the faces of thewheel into ratchet teeth, and providing the necessary striations on theperiphery of the wheel.

This process has certain serious disadvantages.

In the first place, the various machining operations lead to animportant loss of the expensive material of which the wheel is made Theprincipal disadvantage resides, however, in the fact that the variousmachining operations are time consuming, require complex tooling, andhighly skilled labor, which results in a particularly high cost.

It has already been suggested that these abrasive wheels for cigarettelighters be made by stamping them from a plate followed by knurling oftheir external surfaces and nitrating.

This process is, however, scarcely satisfactory in the case of abrasivewheels for automatic lighters, that is to say, wheels driven by ratchetteeth, because it then necessitates the manufacture of a supplementalmember provided with ratchet teeth, which cancels out the advantage ofstamping.

This invention is intended to provide abrasive wheels for cigarettelighters which avoid these disadvantages as a consequence of aparticularly simple structure, as well as methods of manufacture whichmake it possible to produce abrasive wheels for cigarette lighters atspeeds heretofore unknown, with economies in material, machining, andskilled labor, so that the cost of the abrasive wheel may be reduced toa tenth of its present price,

It is an object of the present invention to provide an abrasive wheelfor a cigarette lighter characterized by the fact that it comprises ametal plate bent into a cylindrical shape, with knurling on its externalcylindrical surface and ratchet teeth integral with the plate extendingalong one of its edges.

In a first embodiment the annular cylindrical plate is discontinuous,the annular shape being produced by bringing the two ends of the platetogether. These ends may advantageously be provided with reciprocalinterfitting means.

In another embodiment, the wheel has a continuous annular shape and, onthe edge free of ratchet teeth, terminates in a wall perpendicular tothe axis of the wheel, which thus becomes cupshaped.

It is a further object of the invention to provide a method ofmanufacturing abrasive wheels for cigarette lighters characterized bythe fact that a flat metallic plate of suitable dimensions and providedwith teeth on at least part of its periphery is deformed to impartthereto the cylindrical shape of the wheel.

The toothed flat plate embodiment may advantageously be manufactured bycutting it out, for example in a transfer press, or in a cyclicallyoperating tool.

In a first embodiment of the invention which is particularly useful, theplate is initially rectangular in shape, one of the longitudinal edgesof the plate having teeth formed by shearing to constitute the ratchetteeth of the wheel. The plate is deformed by rolling it up to produce aclosed cylindrical ring by bringing its two ends together.

Advantageously, two extreme ends of the rectangular plate may havemating recesses which interfit when the plate is rolled into a cylinderto prevent separation of these two ends.

In this first embodiment the different plates may be made from a stripof continuous metal which travels through a cyclically operating tool,the different successive plates being detached from each other duringthe final rolling operation which deforms the plate to impart thereto acylindrical shape.

The plate is preferably knurled after it has been rolled into itscylindrical form.

In a second embodiment the flat plate is substantially circular in shapewithh peripheral teeth, and this plate is stamped to form it into theshape of a cylindrical cup. In this embodiment, the flat plate mayadvantageously be formed by cutting the plate from a suitable metallicsheet, with the teeth remaining, after deformation, at the open side ofthe cylindrical cup thus formed.

Such a cup may be formed in a single stamping operation or preferably byseveral successive stamping operations, preferably in a transfer press.

Other advantages and characteristics of the invention will becomeapparent from a reading of the following description ofa preferredembodiment, given purely by way of illustration and example, withreference to the accompanying drawings on which:

FIG. 1 is a schematic view showing in perspective the different steps ofthe process according to the second embodiment of the invention;

FIG. 2 is a top plan view of the plate used in the process according tothe first embodiment of the invention;

FIG. 3 is a side view of an abrasive wheel made from the plate of FIG.2',

FIG. 4 is a diametral sectional view taken through the abrasive wheel ofFIG. 3', and

FIG. 5 is an end view of the abrasive wheel of FIG. 3, which has beenmounted on a sleeve to facilitate its attachment to a shaft.

Referring now to FIG. I, in this first embodiment of the invention aplate I, which is circular in shape, is preferably formed by stamping itfrom a sheet of suitable hard metal and the periphery of this plate hassuitable teeth 2 which are to form the ratchet teeth of the abrasivewheel.

The plate I is stamped in a press to form a cylindrical cup, the bottom3 of which corresponds to the central part of the flat plate, while theannular cylindrical part 4 thereof carries the teeth 2 on its free edge.

In a second stamping step the depth of the cylindrical part 4 isincreaseed to form the cylindrical part 4' and in this state the stampedplate has practically the final dimensions of the abrasive wheel.

After this stamping a central orifice 5 may advantageously be punched inthe bottom 3 to permit the ultimate mounting of the abrasive wheel.

The wheel made in this manner is then striated in a conventional machineto form the knurled surface 4'.

Referring now to FIGS. 2, 3 and 4, in this embodiment of the inventionto a plate of substantially rectangular shape is formed from a strip ofsuitable hard metal. One of the longer sides of this plate is preferablyprovided with teeth 7 formed by shearing for example, while the twoextreme ends of the plate 6 are cut out at 8 to form mating recesseswhich interfit when these two ends are brought together.

The plate 6 is then rolled up to impart thereto an annular cylindricalshape as shown on FIG. 3. At the end of the rolling operation the parts9 of the two ends 10 engage in the recesses 8 so that the two ends arethus connected along a V shaped line shown in FIG. 3. For this reasonsimple friction of the flint against the wheel is incapable of openingup the cylinder formed by the plate, which will therefore always retainits cylindrical shape.

The plate may advantageously be cut in a cyclically operating tool, thedifferent plates 6 being connected one behind the other by strips ofmetal which are eliminated during the rolling of the plate.

When the plate 6 has received it cylindrical shape of polygonal member10 having an inner orifice H for mounting the plate on a suitable shaftis force-fitted into the cylinder.

This member 10 may be provided with a flange 12 extending outwardly in aplane perpendicular to its axis which bears against the surface 13(shown only in FIG. 4) of the plate which is situated opposite toothedsurface 7. After mounting the deformed plate on a suitable tool theknurling 14 is carried out in a conventional manner.

It will be appreciated that the invention results in substantialeconomy, first because of the saving in the expensive material which isutilized for making the wheels, but especially because the processaccording to the invention makes it possible to manufacture a largeseries of wheels on machines operating very rapidly such as transferpresses and cyclically operating tools. The operation of machining theratchet teeth may moreover, be eliminated and replaced by a simplestamping or shearing step.

While the invention which has been described with respect to aparticular embodiment, it will be appreciated that the scope of theinvention is not limited to the details of that embodiment. but may bemodified as to detail without thereby departing from the basicprinciples of the invention.

What is claimed is:

l. Abrasive wheel for a cirgarette lighter which comprises a metallicstrip provided with integral lateral ratchet teeth on one side thereofand having ends which interfit to hold it in a cylindrical shape, theouter cylindrical surface of said strip being knurled.

2. Wheel as claimed in claim I which comprises a mounting hubforce-fitted into said cylindrical plate.

3. Abrasive wheel for a cigarette lighter which comprises a cylinderconsisting essentially of an elongated metal strip having integrallateral ratchet teeth on one side thereof and ends having transverselyprojecting teeth which inter-engage to prevent separation of said endsin a direction which is longitudinal with respect to said strip, theouter cylindrical surface of said strip being knurled.

1. Abrasive wheel for a cirgarette lighter which comprises a metallicstrip provided with integral lateral ratchet teeth on one side thereofand having ends which interfit to hold it in a cylindrical shape, theouter cylindrical surface of said strip being knurled.
 2. Wheel asclaimed in claim 1 which comprises a mounting hub force-fitted into saidcylindrical plate.
 3. Abrasive wheel for a cigarette lighter whichcomprises a cylinder consisting essentially of an elongated metal striphaving integral lateral ratchet teeth on one side thereof and endshaving transversely projecting teeth which inter-engage to preventseparation of said ends in a direction which is longitudinal withrespect to said strip, the outer cylindrical surface of said strip beingknurled.